Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Vega on 11 January 2017, 10:42:42

Title: Aircon trouble
Post by: Vega on 11 January 2017, 10:42:42
I need some input about the aircon system, after 4 to 6 months the system is in my 3.2 V6 Saloon again empty.
I can not find any leaks, no green stuff anywhere.

What has been done.
Condenser is replaced (was leak).
Dryer is replaced (maintenance).
AC pomp is replaced (was leak).
The 2 valves where replaced (where leak).
All maintenance on the aircon system where done by professionals.

The system works works fine, the aircon gets really cold.
But still it is leaking somewhere, so any tips are welcome.
Title: Re: Aircon trouble
Post by: Doctor Gollum on 11 January 2017, 11:52:28
Only things left are the plumbing and the evaporator which lives abovet the back of the heater box and is a genuine dash out job :-\
Title: Re: Aircon trouble
Post by: Vega on 11 January 2017, 19:23:24
Only things left are the plumbing and the evaporator which lives abovet the back of the heater box and is a genuine dash out job :-\

Wouldn't there than leakage to see at the drain hoses under the car?
Title: Re: Aircon trouble
Post by: Doctor Gollum on 11 January 2017, 19:40:41
In an ideal world,  but as likely to collect in the heater ducting...
Title: Re: Aircon trouble
Post by: Kevin Wood on 12 January 2017, 09:48:12
In an ideal world,  but as likely to collect in the heater ducting...

.. and it's high up in the aircon plumbing so it's unlikely that you'd get any oil leakage there, just refrigerant, which will evaporate without trace.
Title: Re: Aircon trouble
Post by: Vega on 12 January 2017, 16:09:59
.. and it's high up in the aircon plumbing so it's unlikely that you'd get any oil leakage there, just refrigerant, which will evaporate without trace.

Okay that is nice  :(
There goes another free day.

Another question about the expansion valve if I look up the number from the EPC I will find two models of expansion valves one 83 mm long and one is 87,8 mm long which one is the right one?

If a replace the evaporator I will also replace the expansion valve at the same time.
Title: Re: Aircon trouble
Post by: Kevin Wood on 12 January 2017, 21:51:53
To be honest, air con is one of the areas where it's a definite advantage to take the car to a specialist rather than DIY. They can check it for leaks, fill it with UV dye so it is easier to find the leaks, and also sniff out the refrigerant with a probe if necessary.

The evaporator isn't a regular failure item, and the expansion valve normally fails closed so cooling performance is poor, if it fails at all. For this reason, I think it's worth getting it checked over by someone with the right kit, as it might well be a seal elsewhere in the system
Title: Re: Aircon trouble
Post by: omega2018 on 13 January 2017, 01:25:38
there are sealants around eg http://www.halfords.com/motoring/engine-oils-fluids/air-con/superseal-air-conditioning-leak-sealant-mrl-3

don't know if they work but no doubt someone here will say (even if they know not) ::)
Title: Re: Aircon trouble
Post by: biggriffin on 13 January 2017, 20:24:04
very unlikely to be evaporator or valve., check around the joint behind the headlight, also the pipe which runs along the l/h chassis rail.


the whole system should be drained then pressure tested with nitrogen. not vacuumed.
Title: Re: Aircon trouble
Post by: Vega on 18 January 2017, 14:58:56
there are sealants around eg http://www.halfords.com/motoring/engine-oils-fluids/air-con/superseal-air-conditioning-leak-sealant-mrl-3

don't know if they work but no doubt someone here will say (even if they know not) ::)

Yes this was put in by the aircon mechanic, did not work for me.

very unlikely to be evaporator or valve., check around the joint behind the headlight, also the pipe which runs along the l/h chassis rail.

the whole system should be drained then pressure tested with nitrogen. not vacuumed.

Yes both where done, all the pipe, hoses, compressor, condenser, dryer and couplings  the system was pressured with 15 psi and there was a slide drop of pressure in the system.
The only thing that is not really tested is the evaporator and expansion valve.

To be honest, air con is one of the areas where it's a definite advantage to take the car to a specialist rather than DIY. They can check it for leaks, fill it with UV dye so it is easier to find the leaks, and also sniff out the refrigerant with a probe if necessary.

The evaporator isn't a regular failure item, and the expansion valve normally fails closed so cooling performance is poor, if it fails at all. For this reason, I think it's worth getting it checked over by someone with the right kit, as it might well be a seal elsewhere in the system

All this where done by specialist. They put extra UV in to see if it leaks somewhere and the sniffer did not find any leaks at that time.

So back to square one again.
Title: Re: Aircon trouble
Post by: Doctor Gollum on 18 January 2017, 15:00:23
Where did they look? Front foot well ventsfor example...
Title: Re: Aircon trouble
Post by: Vega on 18 January 2017, 16:19:17
Almost everywhere.

Yes also drivers front foot well and because of the LHD version the steering column and pedals are in the way but also there is nothing to see, no visible leakage (no green monster).
Only thing I did not check is in the vents, if its a little bit warmer I will try to remove some vent ducts to see if there is something wrong there or if I get my hands on a snake camera I will try that put through the vents.
Title: Re: Aircon trouble
Post by: omega2018 on 18 January 2017, 18:46:32
if I get my hands on a snake camera I will try that put through the vents.
these are ludicrously cheap now eg www.ebay.co.uk/itm/322273426965
Title: Re: Aircon trouble
Post by: Vega on 18 January 2017, 19:27:17
The camera is cheap but I need to buy a Android phone also. :(
Title: Re: Aircon trouble
Post by: omega2018 on 18 January 2017, 23:47:01
The camera is cheap but I need to buy a Android phone also. :(
it will work with a windows laptop "Support systems: Windows 2000 / XP / Vista / 7."

if not many others will, probably find a cheaper one even. or if you are apple a much more expensive one. :(